If the engine is used for a long time, the throttle will of course also deteriorate. We have made lip seal and return spring collar, which are not set as replenishment parts, commercialized, so that we can refresh the throttle. In addition, since a spacer lip seal for suppressing lip seals that boost leakage easily is included, it also serves as a measure against air leakage during boost-up. Each part × 6 pieces / 1 set becomes a set.